I'd have liked to have seen more of the Ents--that is a favorite part of the books for me.

As to the war vs quest issue...that is probably the dreariest part of the books for me, I was always more interested in the quest. The battle scenes in the book and the films are largely generic and interchangeable (I know someone will leap in here to say that was the "message" Tolkien intended, which I think is wrong--mediocre writing is the cause, in my view). I agree too with the criticism that the quest portions of the film are too drawn out (except we get to see the great character Gollum, one of the film's best). Sadly, it didn't have to be that way, but as someone pointed out, Jackson set out to make these as war movies, and that has come at the expense of the most interesting part of the story to me, which is Aragorn's journey, not Frodo's quest. Aragorn is the most interesting character in the book, for me.

I'd also have enjoyed some footage of Orcs at the craft service table.